KR20080025119A - Light-diffusing polycarbonate resin composition and light diffuser plate comprising the resin composition - Google Patents

Abstract

A light-diffusing polycarbonate resin composition which comprises: 100 parts by mass of an aromatic polycarbonate resin which comprises a copolycarbonate having repeating units represented by the following general formulae (I) and (II) and having a content of the repeating units represented by the general formula (II) of 1-30 mass% and a reduced viscosity of 30-71; and 0.01-10 parts by mass of a light diffuser (B) incorporated therein. The light-diffusing polycarbonate resin composition has improved flowability during molding and is excellent in dimensional stability to high temperatures and in luminance and color tone. ® KIPO & WIPO 2008

Description

LIGHT-DIFFUSING POLYCARBONATE RESIN COMPOSITION AND LIGHT DIFFUSER PLATE COMPRISING THE RESIN COMPOSITION}

The present invention provides a light diffusing polycarbonate-based resin composition suitable for a light diffusing plate, an optical lens, a light guide plate (light guide), an optical element of a light diffusing plate, a street lamp cover, or an alternative glass for vehicles and building materials, And a light diffusion plate using the same.

In recent years, the liquid crystal display (LCD) has extended its use not only to a notebook computer (PC) and a monitor but also a general television (TV). In particular, the light-diffusion plate (1-3 mm in thickness) for the direct backlight type | mold used for TV to which brightness is calculated | required is mainly made of acrylic resin about the thing about 20 inches in size.

However, acrylic resins have low heat resistance and high hygroscopicity, and thus have low dimensional stability. As a result, acrylic resins have a problem that warpage deformation occurs in large screen sizes.

Therefore, in recent years, polycarbonate resins (hereinafter abbreviated as PC) resins superior to acrylic resins in terms of heat resistance and hygroscopicity resistance are applied as matrix resins for light diffusion plates, and the demand thereof is expanding.

Conventionally, the composition which made ordinary polycarbonate resin into transparency resin, and mix | blended the light-diffusion agent with this is known (for example, refer patent document 1).

However, Patent Document 1 has superior heat resistance, impact strength, and hygroscopicity compared with acrylic resins, but its transparency is inferior to acrylic resins. Therefore, when a light diffusing agent is blended, it is obtained as a result of light diffusion. Diffused light had the disadvantage that a hue was yellow and a brightness fell.

In addition, in order to manufacture the light diffusing plate for TV of a large screen by injection molding, in the shaping | molding, in polycarbonate resin, because of the residual stress by the lack of fluidity at the time of injection molding, even if it mounts in a backlight, it does not receive light by the heat from a light source. There was a problem that warpage occurred in the diffusion plate. Moreover, there was a problem of yellowing with respect to ultraviolet rays generated from a light source.

That is, in the polycarbonate light diffusing resin, there is a need for improvement in terms of light diffusing characteristics, molding fluidity, and light resistance.

Patent Document 1: Japanese Patent Application Laid-Open No. 1998-46018

Disclosure of the Invention

The present invention has been made to solve the problems of the prior art, and provides a light-diffusion polycarbonate-based resin composition and a light diffusion plate having improved fluidity during molding, excellent heat-resistant dimensional stability, and excellent brightness and color tone. It aims to do it.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to achieve the said objective, the present inventors can improve the fluidity | liquidity of a polycarbonate-type resin composition by mix | blending a light-diffusion agent with the aromatic polycarbonate resin containing a predetermined polycarbonate copolymer, It discovered that the said subject could be solved.

That is, the present invention,

(1) (A) A polycarbonate having a repeating unit represented by the formula (I) and a repeating unit represented by the formula (II), wherein the content of the repeating unit represented by the formula (II) is 1 to 30% by mass, and the viscosity number is 30 to 71 0.01-10 mass parts of (B) light-diffusion agents are mix | blended with respect to 100 mass parts of aromatic polycarbonate resin containing a copolymer, The light-diffusion polycarbonate-type resin composition characterized by the above-mentioned.

[Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms. X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-,- SO _2- , -O-, -CO- or formula III-1 or formula III-2

Represents a bond represented by. R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, and Y represents a linear or branched alkylene group having 2 to 15 carbon atoms. n is an integer from 2 to 200. a, b, c and d each represent an integer of 0 to 4;

(2) It is providing the light-diffusion plate of thickness 0.5-3mm formed by shape | molding the light-diffusion polycarbonate-type resin composition of the said (1) base material.

Best Mode for Carrying Out the Invention

In the present invention, the aromatic polycarbonate resin of component (A) has a repeating unit represented by the formula (I) and a repeating unit represented by the formula (II), and the content of the repeating unit represented by the formula (II) is 1 to 30% by mass. Preferably, the fluidity | liquidity at the time of shaping | molding can be improved by setting it as the composition containing the polycarbonate copolymer of 5-20 mass% and viscosity number 30-71.

The polycarbonate copolymer is a phenol-modified diol copolymerized polycarbonate, and can be produced by a conventional production method called an interfacial polymerization method. That is, it can manufacture by the method of making carbonate precursors, such as dihydric phenol, a phenol modified diol, and phosgene, react. Specifically, in an inert solvent such as methylene chloride, for example, a catalyst or a branching agent is added in the presence of a known acid acceptor or a molecular weight modifier, and divalent phenol, phenol-modified diol, phosgene, etc. The carbonate precursor is reacted.

The polycarbonate copolymer has a repeating unit represented by the following formulas (I) and (II).

Formula I

Formula II

(In formula, R <^3> -R <^4> , X, Y, a-d, and n are mentioned later.)

As bivalent phenol, the compound represented by following formula (Ia) is mentioned.

In the general formula (Ia), R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms, and the alkyl group may be any of linear, branched and cyclic. Specifically as an alkyl group, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group And cyclopentyl group, cyclohexyl group and the like. a and b represent the substitution number of R <^1> and R <^2> , respectively, and are an integer of 0-4. On the other hand, R ¹ is the case of plurality, the plurality of R ¹ may be the same or different from each other, in the case of R ² are a plurality, the plurality of R ² may be the same or different from each other.

X is a single bond, an alkylene group having 1 to 8 carbon atoms (eg, methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, etc.), an alkylidene group having 2 to 8 carbon atoms (eg, ethylidene group, Isopropylidene group), cycloalkylene group having 5 to 15 carbon atoms (e.g., cyclopentylene group, cyclohexylene group, etc.), cycloalkylidene group having 5 to 15 carbon atoms (e.g., cyclopentylidene group, cyclohexylidene group) Etc.), -S-, -SO-, -SO _2- , -O-, -CO- bond or the following general formula (III-1) or the following general formula (III-2)

Represents a bond represented by.

Although various things are mentioned as bivalent phenol represented by the said general formula (Ia), 2, 2-bis (4-hydroxyphenyl) propane [common name: bisphenol A] is suitable especially. As bisphenols other than bisphenol A, For example, Bis (4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 2,2-bis (4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) octane; 2,2-bis (4-hydroxyphenyl) phenylmethane; 2,2-bis (4-hydroxy-1-methylphenyl) propane; Bis (4-hydroxyphenyl) naphthylmethane 1,1-bis (4-hydroxy-t-butylphenyl) propane; 2,2-bis (4-hydroxy-3-bromophenyl) propane; 2,2-bis (4-hydroxy-3,5-tetramethylphenyl) propane; 2,2-bis (4-hydroxy-3-chlorophenyl) propane; 2,2-bis (4-hydroxy-3,5-tetrachlorophenyl) propane; Bis (hydroxyaryl) alkanes such as 2,2-bis (4-hydroxy-3,5-tetrabromophenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclopentane; 1,1-bis (4-hydroxyphenyl) cyclohexane; Bis (hydroxyaryl) cycloalkanes, such as 1, 1-bis (4-hydroxyphenyl) -3, 5, 5- trimethyl cyclohexane, 4, 4'- dihydroxy phenyl ether; Dihydroxyaryl ethers such as 4,4'-dihydroxy-3,3'-dimethylphenyl ether, 4,4'-dihydroxydiphenyl sulfide; Dihydroxy diaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide and 4,4'-dihydroxydiphenyl sulfoxide; Dihydroxy diaryl sulfoxides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide and 4,4'-dihydroxydiphenyl sulfone; Dihydroxy diaryl sulfones, such as 4,4'- dihydroxy-3,3'- dimethyl diphenyl sulfone, Dihydroxy diphenyls, such as 4,4'- dihydroxy diphenyl, 9,9 -Bis (4-hydroxyphenyl) fluorene; Dihydroxy diaryl fluorenes such as 9,9-bis (4-hydroxy-3-methylphenyl) fluorene and 1,3-bis (4-hydroxyphenyl) adamantane; 2,2-bis (4-hydroxyphenyl) adamantane; Dihydroxydiaryl adamantanes such as 1,3-bis (4-hydroxyphenyl) -5,7-dimethyladamantane, bis (4-hydroxyphenyl) diphenylmethane, 4,4 ' -[1,3-phenylenebis (1-methylethylidene)] bisphenol, 10,10-bis (4-hydroxyphenyl) -9-anthrone, 1,5-bis (4-hydroxyphenylthio O) -2,3-dioxapentaene, the (alpha), (omega) -bishydroxyphenyl polydimethylsiloxane compound, etc. are mentioned. These dihydric phenols may be used independently, respectively, or may mix and use 2 or more types.

As a molecular weight modifier, various things can be used as long as it is used for superposition | polymerization of PC resin normally. Specific examples of the monohydric phenol include phenol, on-butylphenol, mn-butylphenol, pn-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, ot-butylphenol, mt-butylphenol, pt-butylphenol, on-pentylphenol, mn-pentylphenol, pn-pentylphenol, on-hexylphenol, mn-hexylphenol, pn-hexylphenol, pt-octylphenol, o-cyclohexylphenol , m-cyclohexylphenol, p-cyclohexylphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, on-nonylphenol, m-nonylphenol, pn-nonylphenol, o-cumylphenol, m -Cumylphenol, p-cumylphenol, o-naphthylphenol, m-naphthylphenol, p-naphthylphenol; 2,5-di-t-butylphenol; 2,4-di-t-butylphenol; 3,5-di-t-butylphenol; 2,5-dicumylphenol; 3,5-dicumylphenol; p-cresol, bromophenol, tribromophenol, monoalkylphenols having linear or branched alkyl groups having an average carbon number of 12 to 35 in the ortho, meta or para position; 9- (4-hydroxyphenyl) -9- (4-methoxyphenyl) fluorene; 9- (4-hydroxy-3-methylphenyl) -9- (4-methoxy-3-methylphenyl) fluorene; 4- (1-adamantyl) phenol etc. are mentioned. Among these monohydric phenols, p-t-butylphenol, p-cumylphenol, p-phenylphenol and the like are preferably used.

As the catalyst, a phase transfer catalyst such as a tertiary amine or a salt thereof, a quaternary ammonium salt, a quaternary phosphonium salt, and the like can be preferably used. Examples of the tertiary amines include triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine, dimethylaniline, and the like, and examples of the tertiary amine salts include hydrochloride salts of these tertiary amines, Bromate, and the like. Examples of quaternary ammonium salts include trimethylbenzylammonium chloride, triethylbenzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide and the like. Tetrabutyl phosphonium chloride, tetrabutyl phosphonium bromide, etc. are mentioned. Each of these catalysts may be used alone or in combination of two or more thereof. Among the catalysts, tertiary amines are preferred, and triethylamine is particularly suitable.

There are various kinds of inert organic solvents. Dichloromethane (methylene chloride); Trichloromethane; Carbon tetrachloride; 1,1-dichloroethane; 1,2-dichloroethane; 1,1,1-trichloroethane; 1,1,2-trichloroethane; 1,1,1,2-tetrachloroethane; 1,1,2,2-tetrachloroethane; Pentachloroethane; Chlorinated hydrocarbons such as chlorobenzene, toluene, acetophenone and the like. Each of these organic solvents may be used alone or in combination of two or more thereof. Among them, methylene chloride is particularly suitable.

As the branching agent, for example, 1,1,1-tris (4-hydroxyphenyl) ethane; α, α ', α "-tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene; 1- [α-methyl-α- (4'-hydroxyphenyl) ethyl] -4- [α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene; 4,4 '-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol; Compounds having three or more functional groups, such as fluoroglycine, trimellitic acid and isatinbis (o-cresol); It is also possible to use a compound having three or more functional groups such as fluoroglycine, trimellitic acid and isatinbis (o-cresol).

The phenol-modified diol used in the present invention is a compound represented by the following general formula (IIa).

[Wherein, R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, and Y represents a linear or branched alkylene group having 2 to 15 carbon atoms. c and d are integers from 0 to 4, n is an integer from 2 to 200.]

As an alkyl group represented by R <^3> , R <^4> , a methyl group, an ethyl group, n-propyl group, and isopropyl group are mentioned. If R ³ is plural, plural R ³ may be the same or different from each other, when R ⁴ is a plurality, the plurality of R ⁴ may be the same or different from each other. Examples of the linear or branched alkylene group having 2 to 15 carbon atoms represented by Y include alkylene groups such as ethylene group, propylene group, butylene group, isobutylene group, pentylene group and isopentylene group, ethylidene group, propylidene group, Alkylidene groups, such as an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group, and an isopentylidene group, are mentioned. It is preferable that n is 2-200, More preferably, it is 6-70.

The phenol-modified diol represented by the above formula (IIa) is a hydroxybenzoic acid or an alkyl ester thereof, a compound derived from an acid chloride and a polyetherdiol, and the like. Although phenol-modified diol can be synthesize | combined by the method proposed by Unexamined-Japanese-Patent No. 1987-79222, Unexamined-Japanese-Patent No. 1985-79072, Unexamined-Japanese-Patent No. 2002-173465, etc., the phenol obtained by these methods It is preferable to add a tablet suitably to a modified diol. As a purification method, the method of distilling excess raw material (for example, parahydroxy benzoic acid) by depressurizing the inside of a system at the back end of reaction, for example, water or alkali aqueous solution (for example, sodium hydrogencarbonate aqueous solution) is carried out with phenol modified diols. The method of washing | cleaning with etc. is preferable.

As hydroxy benzoic acid alkyl ester, hydroxy benzoic acid methyl ester, hydroxy benzoic acid ethyl ester, etc. are typical examples. Polyetherdiol is represented by HO- (YO) _n- H (Y and n are the same as the above), and has a repeating unit which consists of a C2-C15 linear or branched oxyalkylene group. Specifically, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. are mentioned. Polytetramethylene glycol is particularly preferable from the viewpoint of availability and hydrophobicity. The repeating number n of the oxyalkylene group of the polyetherdiol is 2 to 200, preferably 6 to 70. When n is 2 or more, the efficiency at the time of copolymerizing a phenol modified diol is good, and when n is 70 or less, there exists an advantage that the fall of the heat resistance of a PC copolymer is small.

Representative examples of acid chlorides are those obtained from hydroxybenzoic acid and phosgene. More specifically, it can obtain by the method as described in Unexamined-Japanese-Patent No. 2652707. The hydroxybenzoic acid or its alkyl ester may be any of para, meta and ortho, but para is preferred in view of the copolymerization reaction. There is a fear that the ortho is poor in reactivity of copolymerization due to steric hindrance to hydroxyl groups.

In the manufacturing process of a PC copolymer, it is preferable to use a phenol modified diol as methylene chloride solution as much as possible in order to prevent the alteration etc .. When it cannot use as a methylene chloride solution, it can use as aqueous alkali solution, such as NaOH.

In the PC copolymer, increasing the copolymerization amount of the phenol-modified diol improves fluidity but decreases heat resistance. Therefore, it is preferable to select the copolymerization amount of a phenol modified diol by the balance of desired fluidity and heat resistance. If the amount of phenol-modified diol copolymer is too large, as shown in Japanese Patent Laid-Open No. 1987-79222, it becomes an elastomer phase, and there is a possibility that it cannot be applied to applications such as general PC resins. In order to maintain heat resistance of 100 degreeC or more, it is preferable that the quantity of the phenol-modified diol residue contained in a PC copolymer is 1-30 mass% in this invention, More preferably, it is 1-20 mass%, More preferably, 1 To 15 mass%.

In the present invention, the PC copolymer used for the component (A) preferably has a viscosity number of 30 to 71 [corresponding to Mv (viscosity average molecular weight) = 10,000 to 28,100], more preferably 37 to 62 (Mv). = 13,100 to 24,100. If the viscosity number is 30 or more, the mechanical properties are good, and if the viscosity number is 71 or less, the copolymerization effect of the comonomer is exhibited satisfactorily. In order to express high fluidity, a large amount of comonomer is required, but if the viscosity number is 71 or less, the heat resistance does not significantly decrease with respect to the use of the comonomer. In addition, a viscosity number is the value measured based on ISO1628-4 (1999).

In this invention, although the said polycarbonate copolymer can be used independently as aromatic polycarbonate resin which is (A) component, the mixture of the said polycarbonate copolymer and another aromatic polycarbonate resin can also be used.

In the light-diffusion polycarbonate-based resin composition of the present invention, as another aromatic polycarbonate resin used as the component (A), a conventional production method, that is, a polycarbonate such as a bivalent phenol, a phosgene, or a carbonate compound is usually used. The thing manufactured by making a precursor react is mentioned. Specifically, for example, in a solvent such as methylene chloride, a branching agent is added in the presence of a known acid acceptor or a molecular weight modifier, if necessary, by reaction of a dihydric phenol with a carbonate precursor such as phosgene, or It is produced by the transesterification reaction of carbonate precursors, such as a dihydric phenol and diphenyl carbonate.

Although there exist various kinds of dihydric phenols used, 2, 2-bis (4-hydroxyphenyl) propane [common name: bisphenol A] is suitable. As bisphenols other than bisphenol A, what was illustrated by the above-mentioned polycarbonate copolymer can be used, for example.

Examples of the carbonate compound include diaryl carbonates such as diphenyl carbonate, dialkyl carbonates such as dimethyl carbonate and diethyl carbonate. As a molecular weight modifier, various things can be used as long as it is normally used for superposition | polymerization of polycarbonate. Specifically, examples of the monovalent phenol include those exemplified by the aforementioned polycarbonate copolymers such as phenol, o-n-butylphenol, m-n-butylphenol, and p-n-butylphenol. Among monohydric phenols, p-t-butylphenol, p-cumylphenol, p-phenylphenol and the like are preferably used.

In addition, as the branching agent, for example, 1,1,1-tris (4-hydroxyphenyl) ethane like the above-described polycarbonate copolymer; α, α ', α "-tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene; 1- [α-methyl-α- (4'-hydroxyphenyl) ethyl] -4- [α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene; It is also possible to use a compound having three or more functional groups such as fluoroglycine, trimellitic acid and isatinbis (o-cresol).

The other aromatic polycarbonate resin used in the present invention preferably has a viscosity average molecular weight of 10,000 to 100,000, more preferably 15,000 to 40,000.

As another aromatic polycarbonate resin, what was mentioned above or a commercial item can be used.

1: 99-10: 90 are preferable and, as for the mixing ratio of a polycarbonate copolymer and another aromatic polycarbonate resin, 5: 95-50: 50 are more preferable.

The light diffusing agent of the component (B) may be made of a solid which is optically transparent and has a refractive index different from the above-mentioned (A) aromatic polycarbonate resin, and the difference between the refractive index of the component (A) and the component (B) It is preferable that the absolute value of is 0.02-0.2. If the difference in refractive index is in this range, light diffusivity and light transmittance can be made compatible at a high level. This light diffusing agent may use only 1 type selected from a polymer fine particle and an inorganic fine particle, or may use 2 or more types together. In either case, the size average particle diameter is preferably about 0.1 to 200 m.

This average particle diameter is represented by 50% (D50) of the integrated distribution of particle sizes obtained by the laser light scattering method. Moreover, it is preferable that it is narrow about distribution of particle diameter. In this invention, it is more suitable to use a polymer fine particle as (B) component. The use of such polymer fine particles can be realized at a higher level of both the diffusion effect and the total light transmittance in the light diffusion function.

It is preferable that it is spherical from a light-diffusion viewpoint, and, as for the polymer fine particle of (B) component, it is more preferable that it is a form near a true spherical phase. Moreover, as a polymer fine particle, the organic crosslinked particle obtained by superposing | polymerizing a non-crosslinkable monomer and a crosslinkable monomer is mentioned. Examples of the non-crosslinkable monomers include non-crosslinkable vinyl monomers such as acrylic monomers, styrene monomers, and acrylonitrile monomers, and olefin monomers. These can be used individually or in mixture of 2 or more types. It is also possible to use other copolymerizable monomers other than these monomers. Silicone crosslinked particles may be mentioned as other organic crosslinked particles.

As these specific examples, acryl beads, silica beads, silicone resin beads, etc. are mentioned.

As the polymer fine particles, amorphous heat-resistant polymer particles such as polyether sulfone, various epoxy resin particles, melamine resin particles, benzoguanamine resin particles, phenol resin particles, and the like can also be used.

As a specific example of the polymer fine particles used as the light diffusing agent, organic crosslinked particles can be suitably used. In such organic crosslinked particles, examples of the acrylic monomer used as the non-crosslinkable vinyl monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, and ethyl methacrylate. It is possible to use acrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, phenyl methacrylate, etc. alone or in combination. Among these, methyl methacrylate is especially preferable. As the styrene-based monomer, halogenated styrenes such as alkyl styrenes such as styrene, α-methyl styrene, methyl styrene (vinyl toluene), and ethyl styrene, and brominated styrene can be used. In particular, styrene is preferable. As the acrylonitrile monomers, acrylonitrile and methacrylonitrile can be used. Moreover, ethylene, various norbornene-type compounds, etc. can be used as an olefin monomer. Moreover, as another copolymerizable other monomer, glycidyl methacrylate, N-methyl maleimide, maleic anhydride, etc. can be illustrated and it is also possible to have units, such as N-methyl glutalimide, as a result.

On the other hand, as a light diffusing agent which consists of inorganic fine particles, glass filler, calcium carbonate, barium sulfate, silica, talc, mica, wollastonite, etc. are illustrated suitably, and calcium carbonate is mentioned as a suitable thing especially. Although the shape of an inorganic fine particle is not specifically limited, A granular form (including an amorphous form) or plate shape is more preferable than fibrous form. For example, glass beads, glass balloons, glass milled fibers, glass flakes, ultrathin glass flakes (produced by the sol-gel method), amorphous glass, and the like are exemplified. Also in other inorganic fine particles, various shapes can be taken. Moreover, the said inorganic fine particle can use what was surface-treated by various silicone compounds, such as a silane coupling agent and a polyorganohydrogensiloxane compound, a fatty acid ester compound, an olefin compound, etc. Such surface-treated inorganic fine particles are effective in improving thermal stability and hydrolysis resistance. However, titanium oxide is not suitable for use in the present invention because of its high light diffusing ability and large decrease in light transmittance.

Among these inorganic fine particles, glass beads, in particular hollow beads and amorphous powders, plate-like powders and the like of the same material can be generally used.

As the acrylic beads, those having an average diameter of about 0.2 to 20 µm are preferable, and silica beads having an average diameter of about 2 to 20 µm, particularly high purity synthetic silicas having a spherical shape having an average diameter of 2 to 5 µm. It is preferable. As the silicone resin beads, those having an average diameter of about 0.5 to 20 µm are preferable.

And as glass beads, although various glass beads, such as a thing made from low alkali glass (E glass) and the thing made from high refractive index glass (a refractive index is about 1.9-2.2), can be used, it consists of inexpensive E glass The average diameter of about 1-50 micrometers is suitable. Also in the case of using any of the beads, the beads are preferably monodisperse and preferably a spherical one having a retroreflective function.

From the viewpoint of easily obtaining a light-diffusion polycarbonate-based resin composition having excellent transparency (YI), the light-diffusing agent includes silica beads, glass beads, and amorphous powders of crystalline materials excellent in light diffusing function (particularly, crystalline silica powders). This is particularly preferred.

In the present invention, in the (C) thermoplastic acrylic resin used as necessary, the acrylic resin is a polymer having at least one selected from monomer units of acrylic acid, acrylic acid ester, acrylonitrile and derivatives thereof as a repeating unit. It refers to a homopolymer or a copolymer with styrene, butadiene and the like. Specifically, polyacrylic acid, polymethyl methacrylate (PMMA), polyacrylonitrile, ethyl acrylate--2-chloroethyl copolymer, acrylic acid-n-butyl-acrylonitrile copolymer, acrylonitrile- Styrene copolymers, acrylonitrile-butadiene copolymers, acrylonitrile-butadiene-styrene copolymers, and the like. Among these, especially polymethyl methacrylate (PMMA) can be used suitably.

This polymethyl methacrylate (PMMA) is well known, and is usually produced by bulk polymerization of a methyl methacrylate monomer in the presence of a peroxide or an azo polymerization initiator. It is preferable that the molecular weight is about 1000-200,000 from a viewpoint of compatibility with the aromatic polycarbonate resin of (A) component which is a base resin matrix.

The compounding quantity of thermoplastic acrylic resin is 0.001-1 mass part normally with respect to 100 mass parts of aromatic polycarbonate resin of the said (A) component, Preferably it is 0.005-0.5 mass part. When the thermoplastic acrylic resin is 0.001 parts by mass or more, the light guiding property is good and the light-diffusion polycarbonate resin composition having good brightness is obtained. Moreover, within 1 mass part, since there is no phase separation of an acryl-type resin component, and there is no cloudiness, the light-diffusion polycarbonate-type resin composition which is favorable in light guide and high brightness can be obtained.

Moreover, (D) phosphorus stabilizer can be mix | blended with the light-diffusion polycarbonate type resin composition of this invention as needed. Phosphorus stabilizers improve the thermal stability during manufacturing or molding, thereby improving mechanical properties, color and molding stability.

Examples of such phosphorus stabilizers include phosphoric acid compounds and / or aromatic phosphine compounds.

Examples of the phosphoric acid compound include phosphorous acid, phosphoric acid, aphosphonic acid, phosphonic acid, and esters thereof. Specific examples thereof include triphenylphosphite, tris (nonylphenyl) phosphite, and tris (2,4-di-). tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl Phosphite, monodecyldiphenylphosphite, monooctyldiphenylphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritoldiphosphite, 2,2-methylenebis (4,6 -Di-tert-butylphenyl) octylphosphite, bis (nonylphenyl) pentaerythritoldiphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritoldiphosphite, distearylpentaerythritol Diphosphite , Tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monoisogenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4,4'-biphenylene diphosphate tetra And (2,4-di-tert-butylphenyl), benzenephosphonic acid dimethyl, benzenephosphonic acid diethyl, benzenephosphonic acid dipropyl, and the like.

Among them, trisnonylphenyl phosphite, trimethyl phosphate, tris (2,4-di-tert-butylphenyl) phosphite and benzenephosphonic acid dimethyl are preferable.

As an aromatic phosphine compound, the aryl phosphine compound represented by General formula (IV) is mentioned, for example.

(Wherein, X is a hydrocarbon group, at least one is an aryl group having 6 to 18 carbon atoms which may have a substituent.)

As the arylphosphine compound of the formula (IV), for example, triphenylphosphine, diphenylbutylphosphine, diphenyloctadecylphosphine, tris- (p-tolyl) phosphine, tris- (p-nonylphenyl) phosphine, tris -(Naphthyl) phosphine, diphenyl- (hydroxymethyl) -phosphine, diphenyl- (acetoxymethyl) -phosphine, diphenyl- (β-ethylcarboxyethyl) -phosphine, tris- (p -Chlorophenyl) phosphine, tris- (p-fluorophenyl) phosphine, diphenylbenzylphosphine, diphenyl-β-cyanoethylphosphine, diphenyl- (p-hydroxyphenyl) -phosphine, Diphenyl-1,4-dihydroxyphenyl-2-phosphine, phenylnaphthylbenzylphosphine and the like.

Especially, triphenyl phosphine can be used suitably.

The said phosphorus stabilizer may be used individually by 1 type, or may be used in combination of 2 or more type.

The compounding quantity of the phosphorus stabilizer used by this invention is 0.001-1 mass part normally with respect to 100 mass parts of aromatic polycarbonate resin which is (A) component, Preferably it is 0.005-0.5 mass part, More preferably, it is 0.01-0.1 mass It is wealth.

If the compounding quantity of a phosphorus stabilizer is in the said range, the thermal stability at the time of shaping | molding will improve.

In this invention, (E) organopolysiloxane can be mix | blended as needed.

The organopolysiloxane compound used in the present invention has at least one group selected from an alkoxy group, a vinyl group and a phenyl group, for example, a reactive silicone compound in which at least one group of a methoxy group, a vinyl group and a phenyl group is introduced into a silicone compound. (Organosiloxane etc.) etc. are preferable.

The said (E) component has the effect which improves the thermal stability at the time of shaping | molding more, such as yellowing by heat deterioration at the time of shaping | molding, the appearance defects, such as silver (silver), etc., prevention of bubble mixing.

The compounding quantity of the said (E) component can be suitably selected from the range of 0.01-1 mass part normally with respect to 100 mass parts of aromatic polycarbonate resin which is (A) component.

 If the compounding quantity is 0.01 parts by mass or more, the thermal stabilization effect by the above-mentioned formulation is sufficiently exhibited, and if it is 1 part by mass or less, haze or the like does not occur in the molded article.

In the light-diffusion polycarbonate-based resin composition of the present invention, the ultraviolet absorber of (F) component used as needed can use the ultraviolet absorber whose maximum wavelength in an ultraviolet absorption spectrum is 290-330 nm. As such a ultraviolet absorber, what is chosen from a malonic acid ester type compound, an oxalylanilide type compound, and a benzotriazole type compound is preferable. These can be used individually by 1 type or in combination of 2 or more type.

Examples of the malonic acid ester compound include benzylidene bis diethyl malonate, 4-methoxyphenyl-methylene-dimethyl ester, and the like. Examples of the oxalylanilide compound include oxalylanilide compounds having a hydrocarbon group having 1 to 12 carbon atoms. As a benzotriazole type compound, the acryl polymer which has a side chain which has a benzotriazole type | system | group backbone is preferable, As such, 2- (5-t-octyl-2-hydroxy to a polymethyl methacrylate (PMMA) side chain is preferable. The compound etc. which the phenyl) benzotriazole group couple | bonded are mentioned.

It is preferable that the compounding quantity of the ultraviolet absorber of (F) component is 0.05-5 mass parts with respect to 100 mass parts of aromatic polycarbonate resin of (A) component, More preferably, it is 0.1-3 mass parts. If it is 0.05 mass part or more, favorable light resistance will be obtained, and if it is within 5 mass parts, the fall of an initial color tone can be suppressed.

Moreover, in this invention, in order to improve steam resistance (hydrolysis resistance), (G) alicyclic epoxy compound can be mix | blended as needed.

The alicyclic epoxy compound as the component (G) used in the present invention means an alicyclic epoxy group, that is, a cyclic aliphatic compound having an epoxy group in which an oxygen atom is added to an ethylene bond in an aliphatic ring, and specifically, the formulas (V) to (XIV). The compound represented is used suitably.

(R: H or CH ₃ )

(R: H or CH ₃ )

(a + b = 1 or 2)

(a + b + c + d = 1 to 3)

(a + b + c = n (integer), R: hydrocarbon group)

(n: integer)

(R: hydrocarbon group)

(n: integer, R: hydrocarbon group)

Especially, the compound represented by general formula (V), general formula (X), or general formula (XIV) is used more preferable at the point which is excellent in compatibility with aromatic polycarbonate resin, and does not impair transparency.

By mix | blending the alicyclic epoxy compound which is said (G) component, transparency of the resin composition of this invention improves further, and steam resistance (hydrolysis resistance) also improves.

The compounding quantity of the alicyclic epoxy compound which is the said (G) component is 0.01-1 mass part normally with respect to 100 mass parts of aromatic polycarbonate resin which is (A) component, Preferably it is 0.02-0.2 mass part.

Transparency and steam resistance improve that compounding quantity is 0.01 mass part or more.

Moreover, if it is 1 mass part or less, phase separation does not occur and transparency is also favorable.

Moreover, various additives can be mix | blended with the light-diffusion polycarbonate type resin composition of this invention as needed other than each said component. For example, antioxidants, such as an obstacle phenol type and ester type, light stabilizers, such as an obstacle amine type, a flame retardant, a flame retardant adjuvant, a mold release agent, an antistatic agent, a coloring agent, etc. which are used normally are mentioned.

The light-diffusion polycarbonate resin composition of this invention can be obtained by mix | blending said each component and melt-kneading as needed. Mixing and melt kneading | mixing can employ | adopt a conventional method, For example, it can carry out by a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, a corander, a multi screw extruder, etc.

As for the heating temperature in melt kneading, 250-300 degreeC is suitable normally. Since the fluidity of resin is remarkably improved and the retention stability in an injection molding machine etc. is improved, this light-diffusion polycarbonate resin composition can be injection-molded as a light-diffusion plate for 20-inch or more LCD, and acrylic resin The problem of heat resistance due to the light diffusion plate, lack of hygroscopicity resistance and warpage due to enlargement can be solved, and a large and thin (2 mm) light diffusion plate having excellent heat resistance and hygroscopicity with a polycarbonate resin can be formed.

The light diffusion plate can be suitably used in the field of liquid crystal display, the use of optical components, and the glass replacement. As an optical component, optical elements, such as an optical lens, a light-guide plate (light guide), and a light-diffusion plate, etc. are mentioned, for example, Street light cover, laminated glass for vehicles, and building materials etc. are mentioned as a glass replacement use.

Next, although an Example demonstrates this invention still in detail, this invention is not limited at all to these examples.

Production Example [Production of Polycarbonate Copolymer]

Polycarbonate copolymer was prepared as follows.

[Synthesis of polytetramethylene glycol-bis (4-hydroxybenzoate)]

Under nitrogen, 100 parts by mass of polytetramethylene glycol (PTMG, Mn = 2000) and 16.7 parts by mass of methyl p-hydroxybenzoic acid were heated to 210 ° C in the presence of 0.5 parts by mass of dibutyltin oxide, and methanol was distilled off.

The inside of the reaction system was subjected to reduced pressure, and excess p-hydroxybenzoic acid methyl ester was distilled off. After dissolving the reaction product in methylene chloride, 8 mass% sodium bicarbonate aqueous solution was added to the methylene chloride solution, mixed vigorously for 20 minutes, and the methylene chloride phase was collected by centrifugation. The methylene chloride phase was concentrated under reduced pressure to give polytetramethylene glycol-bis (4-hydroxybenzoate). As a result of quantifying p-hydroxybenzoic acid and methyl p-hydroxybenzoate by high performance liquid chromatography (HPLC), p-hydroxybenzoic acid was 10 mass ppm or less and methyl p-hydroxybenzoate was 0.2 mass%.

HPLC measurement method is as follows. Using ODS-3 column by GL Science, it measured on the conditions of the column temperature of 40 degreeC, 0.5% phosphoric acid aqueous solution, acetonitrile 1: 2 mixed solvent, and flow rate of 1.0 mL / min. Quantification was calculated based on the calibration curve by the standard.

(Preparation of polycarbonate oligomer solution)

To a 5.6 mass% sodium hydroxide aqueous solution, 2000 ppm of sodium isocyanate is added to bisphenol A (BPA) to be dissolved later, and BPA is dissolved so that the BPA concentration is 13.5 mass%, and the aqueous sodium hydroxide solution of BPA is added thereto. Prepared. At a flow rate of 40 L / hr of sodium hydroxide aqueous solution of BPA and 15 L / hr of methylene chloride, phosgene was continuously passed through a tubular reactor having a diameter of 6 mm and a tube length of 30 m at a flow rate of 4.0 kg / hr. The tubular reactor had a jacket portion, and the cooling water was passed through the jacket to maintain the temperature of the reaction solution at 40 ° C or lower. The reaction liquid exiting the tubular reactor was continuously introduced into a modeled reactor with a 40 liter baffle with a retrogression, where additionally 2.8 L / hr aqueous sodium hydroxide solution of BPA, 0.07 aqueous solution of 25 mass% sodium hydroxide 0.07 L / hr, 17 L / hr water, and 1 mass% triethylamine aqueous solution were added at 0.64 L / hr, and reaction was performed. The reaction liquid overflowing from the tank reactor was continuously extracted, and the water phase was separated and removed, and the methylene chloride phase was collected.

The polycarbonate oligomer thus obtained was 329 g / L in concentration and 0.74 mol / L in chloroformate group.

(Manufacture of PCC1)

15L polycarbonate oligomer solution prepared above, 8.6L methylene chloride, polytetramethylene glycol-bis (4-hydroxybenzoate) prepared in a 50L tank reactor equipped with a baffle plate, paddle stirring blade and cooling jacket Ate) 325 g (average molecular weight of the PTMG chain = 2000) and 8.5 mL of triethylamine were added thereto, and 2673 g of a 6.4 mass% aqueous sodium hydroxide solution was added thereto under stirring, followed by 10 minutes of polycarbonate oligomer and polytetramethylene glycol-bis ( 4-hydroxybenzoate) was reacted.

In this polymerization solution, a methylene chloride solution of pt-butylphenol (PTBP) (110 g of PTBP dissolved in 1.0 L of methylene chloride) and an aqueous sodium hydroxide solution of BPA (518 g of NaOH and 1.7 g of sodium citrate were dissolved in 7.6 L of water). And 862 g of BPA dissolved in an aqueous solution) was added to carry out the polymerization reaction for 30 minutes.

For dilution, 15 L of methylene chloride was added and stirred for 10 minutes, followed by separation into an organic phase containing polycarbonate and an aqueous phase containing excess BPA and NaOH to isolate the organic phase.

The methylene chloride solution of the polycarbonate thus obtained was washed sequentially with 15 vol% of 0.03 mol / L NaOH aqueous solution and 0.2 N hydrochloric acid, and then the electrical conductivity in the aqueous phase after washing was 0.01 μS / m or less. The washing was repeated with pure water until

The methylene chloride solution of polycarbonate obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 100 ° C under reduced pressure.

The amount of polytetramethylene glycol-bis (4-hydroxybenzoate) residues determined by NMR was 5.0 mass%.

The viscosity number measured based on ISO 1628-4 (1999) was 39.7.

(Manufacture of PCC2)

15L polycarbonate oligomer solution prepared above, 8.6L methylene chloride, polytetramethylene glycol-bis (4-hydroxybenzoate) prepared in a 50L tank reactor equipped with a baffle plate, paddle stirring blade and cooling jacket 8) 650 g (average molecular weight of PTMG chain = 2000) and 8.5 mL of triethylamine were added thereto, and 2673 g of a 6.4% by mass aqueous sodium hydroxide solution was added thereto under stirring, followed by 10 minutes of polycarbonate oligomer and polytetramethylene glycol-bis ( 4-hydroxybenzoate) was reacted.

Methylene chloride solution of PTBP (containing 145 g of PTBP in 1.0 L of methylene chloride) and BPA aqueous solution of sodium hydroxide (a solution of NaOH 518 g and 1.7 g of sodium citrate in 7.6 L of water) were dissolved in this polymerization solution. And the polymerization reaction was performed for 30 minutes.

For dilution, 15 L of methylene chloride was added and stirred for 10 minutes, followed by separation into an organic phase containing polycarbonate and an aqueous phase containing excess BPA and NaOH to isolate the organic phase.

The methylene chloride solution of the polycarbonate thus obtained was washed sequentially with 15 vol% of 0.03 mol / L NaOH aqueous solution and 0.2 N hydrochloric acid, and then the electrical conductivity in the aqueous phase after washing was 0.01 μS / m or less. The washing was repeated with pure water until

The methylene chloride solution of polycarbonate obtained by washing was concentrated and pulverized, and the obtained flakes were dried at 100 ° C under reduced pressure.

The amount of the polytetramethylene glycol-bis (4-hydroxybenzoate) residue determined by NMR was 10.7 mass%.

The viscosity number measured based on ISO 1628-4 (1999) was 34.5.

(Measurement of Copolymer)

¹ H-NMR of the copolymer was measured, and each proton (underscore) was attributed as follows.

δ 1.4-1.9: the _{BPA C H 3, -O-CH} 2 - CH 2 - CH 2 -CH 2 -

_{δ 3.3-3.5: -O- CH 2 -CH 2} -CH 2 - CH 2 -

δ 4.3-4.4: -CO-O- CH ₂ -CH ₂ -CH ₂ -CH _2-

The molar ratio of the phenol-modified diol carbonate part represented by general formula (II) and the BPA carbonate part represented by general formula (I) from each integration value was computed by weight conversion, after calculating with the following formula. As a result, the copolymerization amount of the phenol-modified diol carbonate portion represented by the formula (II) and the BPA carbonate portion represented by the formula (I) was 10.7 mass%.

(formula)

The calculation formula is shown below.

When the integral value of δ 1.4-1.9 is 929.5, the integral value of δ 3.3-3.5 is 179.5, and the integral value of δ 4.3-4.4 is 5.9, the repetition number n = 179.5 ÷ 5.9 + 1 = 31.4

BPA = [(929.5-179.5-5.9) / 6] = 124.0

Phenol-modified diol = (5.9 / 4) = 1.475

The molar ratio of BPA carbonate part is 98.8 mol% by the following calculation.

[(929.5-179.5-5.9) / 6] / {(5.9 / 4) + [(929.5-179.5-5.9) / 6]} * 100 = 98.8 mol%

The molar ratio of a phenol-modified diol carbonate part is 1.18 mol% by the following calculation.

(5.9 / 4) / {(5.9 / 4) + [((929.5-179.5-5.9) / 6]} * 100 = 1.18 mol%

Therefore, the copolymerization amount [mass%] of a phenol modified diol carbonate part becomes 10.7 mass% by the following formula.

1.18 × (136 + 120 + 31.4 × 72 + 12 + 16) ÷ (1.18 × (136 + 120 + 31.4 × 72 + 12 + 16) + 98.8 × 254) × 100 = 10.7 mass%

Examples 1-9, Comparative Examples 1 and 2

Using the following materials for Examples and Comparative Examples, each component was supplied to a single-axis kneading extruder (model name: VS-40, manufactured by Taguchi Plastics Machinery Co., Ltd.) having a diameter of 40 mm at a blending ratio shown in Table 1, and a kneading temperature was 280 ° C. And pelletized at a screw rotation speed of 100 rpm.

In addition, in Table 1, the mass% of each additive is a value with respect to aromatic PC resin.

[Combination Components]

(A) Aromatic PC Resin

PCC1: Polycarbonate-based copolymer according to the preparation example (PTMG content 5% by mass)

PCC2: Polycarbonate-based copolymer according to the production example (PTMG content 10.7% by mass)

PC1: polycarbonate polymer teflon FN1500 [trade name, product of Idemitsu Kosan Co., Ltd., viscosity average molecular weight 14500, refractive index 1.585]

(B) light diffusing agent

MBX20: acrylic crosslinked particles [trade name, manufactured by Sekisui Plastic Co., Ltd., average particle diameter: 20 μm]

KMP590: Silicone resin particles [trade name, manufactured by Shin-Etsu Silicone Co., Ltd., average particle diameter of 2 μm]

(C) thermoplastic acrylic resin

BR-83: Polymethyl methacrylate (PMMA), diamond BR-83 [trade name, Mitsubishi Rayon Co., Ltd., viscosity average molecular weight 40000]

(D) Phosphorus stabilizer

JC-263: triphenylphosphine [trade name, manufactured by Johoku Chemical Co., Ltd.]

(E) organopolysiloxane

KR511: organopolysiloxane having a phenyl group, a methoxy group and a vinyl group [trade name, manufactured by Shin-Etsu Silicone Co., Ltd., refractive index 1.518]

(F) UV absorbers

HOSTAVIN B-CAP: Malonic acid ester ultraviolet absorber [trade name, made by Clariant Co., Ltd.]

Sanduvor VSU: Oxalyl anilide ultraviolet absorber [trade name, made by Clariant Corporation]

HOSTAVIN RP-25: malonic acid ester ultraviolet absorber [trade name, made by Clariant Corporation]

ULS1635: Benzotriazole-based ultraviolet absorber [trade name, manufactured by Ipposha Oil Holding Co., Ltd.]

(G) alicyclic epoxy compound

2021P: Celoxide 2021P [trade name, manufactured by Daicel Chemical Industries, Ltd., compound of formula V]

As evaluation of the fluidity, the flow value (Q value) and spiral flow length (SFL value) of the obtained pellets were measured by the following method.

In addition, as evaluation of moldability, the obtained pellets were subjected to a 650 ton injection molding machine (model name: MD650AP, manufactured by Niigata Machine Techno Co., Ltd.), and a light diffusion plate having a thickness of 32 inches (81.3 cm) and a thickness of 2 mm at a molding temperature of 280 ° C and a mold temperature of 100 ° C. Molded.

Moreover, as evaluation of color tone and light resistance, the obtained pellets were evaluated by a 40-ton injection molding machine (model name: EC40N, manufactured by Toshiba Machine Co., Ltd.) under conditions of a molding temperature of 300 ° C. and a mold temperature of 100 ° C. (140 mm in width and width). 2 mm thickness), and the light transmittance, haze, YI, and light resistance were measured.

Each performance was evaluated by the following method.

(1) liquidity

-Q value: The molten resin amount (mL / sec) which flowed out from the nozzle of diameter 1mm and length 10mm was measured under the pressure of 280 degreeC and 15.7 Mpa based on JISK7210 using the expensive flow tester. The flow value (Q value) increases with the decrease of melt viscosity.

SFL: It evaluated on the conditions of injection molding temperature of 280 degreeC, injection pressure of 7.8 MPa, mold temperature of 80 degreeC, and thickness of 2 mm.

(2) formability

The thickness tolerance of the 32-inch and 2 mm light-diffusion plate injection-molded on the said conditions made the pass ((circle)) within ± 100 micrometers.

(3) transmittance

It measured based on the measuring method of JISK7105.

(4) haze

It measured based on the measuring method of JISK7105.

(5) hue evaluation (YI)

Using a spectrophotometer (manufactured by Gretagmacbeth Inc., LCM2020 Plus), YI, chromaticity (x, y) and 400 nm light transmittance were measured under conditions of an F light source and a 10 degree field of view.

(6) light resistance test

Color difference (DELTA) E after irradiation for 24 hours was measured in 65 degreeC atmosphere using the fluorescent UV lamp as a light source using the light tester (UVCON UC-1 by the Atlas company).

In the light diffusing plate formed in each example, no burning or gas (bubble) was seen on the appearance, and the thickness tolerance was within ± 100 μm.

(7) Retention stability test (△ YI)

Using a spectrophotometer (manufactured by Gretag Macbeth Co., Ltd., LCM2020 Plus), the difference between the YI of the color plate molded without staying in the 40-ton injection molding machine and the color plate after the stay for 15 minutes was measured and evaluated by C light source.

The above evaluation results are collectively shown in Table 2.

The light-diffusion polycarbonate-based resin composition of the present invention has a relatively large liquid crystal display field of 20 inches or more because the fluidity is improved, the heat-resistant dimensional stability is excellent, the light-diffusing light is bright, and the yellow color of the color is reduced. In addition to being suitable for light diffusing plate applications in light and the like, optical elements such as optical lenses, light guide plates (light guides), light diffusing plates, and the like can be suitably used for glass replacement applications in street lamp covers, vehicles, and building materials.

Claims (13)

(A) a polycarbonate copolymer having a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II), wherein the content of the repeating unit represented by the general formula (II) is 1 to 30% by mass, and the viscosity number is 30 to 71; 0.01-10 mass parts of (B) light-diffusion agents are mix | blended with respect to 100 mass parts of aromatic polycarbonate resins containing, The light-diffusion polycarbonate-type resin composition characterized by the above-mentioned. Formula I

Formula II

[Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms. X is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, -S-, -SO-,- SO _2- , -O-, -CO- or formula III-1 or formula III-2

Represents a bond represented by. R ³ and R ⁴ each independently represent an alkyl group having 1 to 3 carbon atoms, and Y represents a linear or branched alkylene group having 2 to 15 carbon atoms. n is an integer from 2 to 200. a, b, c and d each represent an integer of 0 to 4; The method of claim 1, In formula (II), Y is selected from -CH ₂ -CH ₂ -CH ₂ -CH _2- , -CH ₂ -CH ₂ -CH ₂ -CH (CH ₃ )-, -CH ₂ -CH ₂ -CH _2- The light-diffusion polycarbonate type resin composition which is 1 type, or a mixture thereof. The method according to claim 1 or 2, Furthermore, (C) 0.01-5 mass parts of thermoplastic acrylic resins are mix | blended, The light-diffusion polycarbonate-type resin composition characterized by the above-mentioned. The method according to any one of claims 1 to 3, Furthermore, the light-diffusion polycarbonate-type resin composition formed by mix | blending 0.001-1 mass part of (D) phosphorus stabilizers. The method according to any one of claims 1 to 4, Furthermore, (E) Light-diffusion polycarbonate resin composition formed by mix | blending 0.01-1 mass part of organopolysiloxane. The method of claim 5, wherein The said (E) organopolysiloxane is a light-diffusion polycarbonate-type resin composition whose difference in refractive index with (A) component is 0.1 or less organopolysiloxane. The method according to any one of claims 1 to 6, Furthermore, the light-diffusion polycarbonate resin composition formed by mix | blending 0.05-5 mass parts of (F) ultraviolet absorbers. The method according to any one of claims 1 to 7, Furthermore, the light-diffusion polycarbonate type resin composition formed by mix | blending 0.001-1 mass part of (G) alicyclic epoxy compounds. The method according to any one of claims 3 to 8, The light-diffusion polycarbonate resin composition whose viscosity average molecular weights of said (C) thermoplastic acrylic resin are 1000-200000. The method according to any one of claims 1 to 9, (B) Component is 1 type (s) or 2 or more types selected from crosslinked polymethylmethacrylate resin particle, silicone resin particle, polyorgano silsesquioxane particle, silica particle, quartz particle, silica fiber, quartz fiber, glass fiber Phosphorus light-diffusion polycarbonate resin composition. The method according to any one of claims 1 to 10, The light-diffusion polycarbonate resin composition whose average particle diameter of (B) component is 1-200 micrometers. The method according to any one of claims 7 to 11, The light-diffusion polycarbonate resin composition whose (F) component is a light-resistant agent whose maximum wavelength in an ultraviolet absorption spectrum is 290-330 nm. A light diffusing plate having a thickness of 0.5 to 3 mm, wherein the light diffusing polycarbonate resin composition according to any one of claims 1 to 12 is molded.